Nuclear Theory·nucl-th

Tuesday·April 2, 2024

15 papers—8 primary·7 cross-listed

09
Quantum simulation of entanglement and hadronization in jet production: lessons from the massive Schwinger model
Adrien Florio🇺🇸 · David Frenklakh🇺🇸 · Kazuki Ikeda🇺🇸 · Dmitri E. Kharzeev🇺🇸 · Vladimir Korepin🇺🇸 · Shuzhe Shi🇺🇸 · Kwangmin Yu🇺🇸
The possible link between entanglement and thermalization, and the dynamics of hadronization are addressed by studying the real-time response of the massive Schwinger model coupled to external sources. This setup mimics the production and fragmentation of quark jets, as the Schwinger model and QCD share the properties of confinement and chiral symmetry breaking. By using quantum simulations on classical hardware, we study the entanglement between the produced jets, and observe the growth of the corresponding entanglement entropy in time. This growth arises from the increased number of contributing eigenstates of the reduced density matrix with sufficiently large and close eigenvalues. We also investigate the physical nature of these eigenstates, and find that at early times they correspond to fermionic Fock states. We then observe the transition from these fermionic Fock states to meson-like bound states as a function of time. In other words, we observe how hadronization develops in real time. At late times, the local observables at mid-rapidity (such as the fermion density and the electric field) approach approximately constant values, suggesting the onset of equilibrium and approach to thermalization.
↳ hep-phhep-thnucl-thquant-phPRD(2024)·52 citations
10
Solving reaction dynamics with quantum computing algorithms
Ronen Weiss🇺🇸 · Alessandro Baroni🇺🇸 · Joseph Carlson🇺🇸 · Ionel Stetcu🇺🇸
The description of quantum many-body dynamics is extremely challenging on classical computers, as it can involve many degrees of freedom. On the other hand, the time evolution of quantum states is a natural application for quantum computers that are designed to efficiently perform unitary transformations. In this paper, we study quantum algorithms for response functions, relevant for describing different reactions governed by linear response. We focus on nuclear-physics applications and consider a qubit-efficient mapping on the lattice, which can efficiently represent the large volumes required for realistic scattering simulations. For the case of a contact interaction, we develop an algorithm for time evolution based on the Trotter approximation that scales logarithmically with the lattice size, and is combined with quantum phase estimation. We eventually focus on the nuclear two-body system and a typical response function relevant for electron scattering as an example. We also investigate ground-state preparation and examine the total circuit depth required for a realistic calculation and the hardware noise level required to interpret the signal.
↳ quant-phnucl-thPRC(2025)·13 citations
11
New method for the solution of the two-body Dirac equation for the positronium bound states
E.M. Tursunov · Sh.G. Norbutaev · B.A. Fayzullaev
A new theoretical method is developed to solve the two-body bound-state Dirac equation for positronium. Only Coulomb potential was included in the Dirac Hamiltonian. It is shown that the two-body Dirac Hamiltonian can be written in the Hermitian matrix form of the 4 $\times$ 4 size and diagonalized in the momentum-state representation. Numerical results for the energy spectrum of the para- and ortho-positronium ground states performed within the variational method using the harmonic oscillator basis functions are in good agreement with a high-precision finite-element method of T.C. Scott et al. After the Fourier transformation into the coordinate-state representation the bound state wave functions of the para-Ps and ortho-Ps do not contain any singularity at the origin in contrast to the method mentioned above. The weights of the large-small and small-large components of the ground state wave functions are estimated to be of order 10 $^{- 6}$ , while the weight of the small-small component is of order 10 $^{- 12}$ .
↳ hep-phhep-exnucl-thquant-ph1 citation
12
Order of the SU(N_f) x SU(N_f) chiral transition via the functional renormalization group
G. Fejos🇯🇵 · T. Hatsuda🇯🇵
Renormalization group flows of the $S U (N_{f}) \times S U (N_{f})$ symmetric Ginzburg-Landau potential are calculated for a general number of flavors, $N_{f}$ . Our approach does not rely on the $ϵ$ expansion, but uses the functional renormalization group, formulated directly in $d = 3$ spatial dimensions, with the inclusion of all possible (perturbatively) relevant and marginal operators, whose number is considerably larger than those in $d = 4$ . We find new, potentially infrared stable fixed points spanned throughout the entire $N_{f}$ range. By conjecturing that the thermal chiral transition is governed by these ``flavor continuous" fixed points, stability analyses show that for $N_{f} \geq 5$ the chiral transition is of second-order, while for $N_{f} = 2, 3, 4$ , it is of first-order. We argue that the $U_{A} (1)$ anomaly controls the strength of the first-order chiral transition for $N_{f} = 2, 3, 4$ , and makes it almost indistinguishable from a second-order one, if it is sufficiently weak at the critical point. This could open up a new strategy to investigate the strength of the $U_{A} (1)$ symmetry breaking around the critical temperature.
↳ hep-phhep-lathep-thnucl-thPRD(2024)·38 citations
13
A new approach for deducing rms proton radii from charge-changing reactions of neutron-rich nuclei and the reaction-target dependence
J.-C. Zhang · B.-H. Sun · I. Tanihata · R. Kanungo · C. Scheidenberger · S. Terashima · Feng Wang · F. Ameil · J. Atkinson · Y. Ayyad · S. Bagchi · D. Cortina-Gil and 26 other authors
We report the charge-changing cross sections ( $σ_{cc}$ ) of 24 $p$ -shell nuclides on both hydrogen and carbon at about 900 $A$ MeV, of which $^{8, 9}$ Li, $^{10 \textendash 12}$ Be, $^{10, 14, 15}$ B, $^{14, 15, 17 \textendash 22}$ N and $^{16}$ O on hydrogen and $^{8, 9}$ Li on carbon are for the first time. Benefiting from the data set,we found a new and robust relationship between the scaling factor of the Glauber model calculations and the separation energies of the nuclei of interest on both targets.This allows us to deduce proton radii ( $R_{p}$ ) for the first time from the cross sections on hydrogen. Nearly identical $R_{p}$ values are deduced from both target data for the neutron-rich carbon isotopes, however, the $R_{p}$ from the hydrogen target is systematically smaller in the neutron-rich nitrogen isotopes.This calls for further experimental and theoretical investigations.
↳ nucl-exnucl-thSci.Bull.(2024)·20 citations
14
Total Gluon Helicity from Lattice without Effective Theory Matching
Zhuoyi Pang🇨🇳 · Fei Yao🇨🇳 · Jian-Hui Zhang🇨🇳
We propose two approaches for extracting the total gluon helicity contribution to proton spin from lattice QCD, one from local operator matrix elements in a fixed gauge accessible on lattice with feasible renormalization, and the other from gauge-invariant nonlocal gluon correlators. Neither of these approaches requires a matching procedure when converted to the MS scheme. Our proposal resolves a long-standing inconsistency in the literature regarding lattice calculations of the total gluon helicity, and has the potential to greatly facilitate these calculations.
↳ hep-phhep-latnucl-exnucl-thJHEP(2024)·6 citations
15
Efficient and precise quantum simulation of ultra-relativistic quark-nucleus scattering
Sihao Wu🇨🇳 · Weijie Du🇺🇸 · Xingbo Zhao🇨🇳 · James P. Vary🇺🇸
We present an efficient and precise framework to quantum simulate the dynamics of the ultra-relativistic quark-nucleus scattering. This framework employs the eigenbasis of the asymptotic scattering system and implements a compact scheme for encoding this basis upon lattice discretization. It exploits the operator structure of the light-front Hamiltonian of the scattering system, which enables the Hamiltonian input that utilizes the quantum Fourier transform for efficiency. Our framework simulates the scattering by the efficient and precise algorithm of the truncated Taylor series. The qubit cost of our framework scales logarithmically with the Hilbert space dimension of the scattering system. The gate cost has optimal scaling with the simulation error and near optimal scaling with the simulation time. These scalings make our framework advantageous for large-scale dynamics simulations on future fault-tolerant quantum computers. We demonstrate our framework with a simple scattering problem and benchmark the results with those from the Trotter algorithm and the classical calculations, where good agreement between the results is found. Our framework can be generalized to simulate the dynamics of various scattering problems in quantum chromodynamics.
↳ quant-phhep-thnucl-thPRD(2024)·19 citations

Affiliations

first authorsco-authorsvia INSPIRE

Quantum simulation of entanglement and hadronization in jet production: lessons from the massive Schwinger model

Solving reaction dynamics with quantum computing algorithms

New method for the solution of the two-body Dirac equation for the positronium bound states

Order of the SU(N_f) x SU(N_f) chiral transition via the functional renormalization group

A new approach for deducing rms proton radii from charge-changing reactions of neutron-rich nuclei and the reaction-target dependence

Total Gluon Helicity from Lattice without Effective Theory Matching

Efficient and precise quantum simulation of ultra-relativistic quark-nucleus scattering

Affiliations